Associations between adolescent perceived loneliness and hair cortisol concentration

Introduction: Adolescents experience high levels of loneliness, which is linked to poor health in adulthood. Loneliness may contribute to poor health through chronic dysregulation of the hypothalamic-pituitary-adrenal axis. In this analysis, we examined the associations between survey- and ecological momentary assessment (EMA)-based measures of loneliness and hair cortisol concentrations (HCC) in a sample of 1102 adolescents and assessed sex differences in this relationship.

Methods: Data came from wave 1 of the Adolescent Health and Development in Context study. We conducted a series of multivariable linear regression models to examine the associations between loneliness and HCC. Models were adjusted for adolescent and caregiver demographics, adolescent clinical factors, adolescent hair care practices, and adolescent lifetime mental health diagnosis and current psychotropic medication use. An interaction term between sex and loneliness was added to assess for effect moderation.

Results: In our sample, the mean HCC was 1.35 pg/mg (SD=1.1). The mean for the unstandardized survey loneliness measure was 1.79 (SD=0.79) for the total analytic sample. The unstandardized mean for the EMA loneliness measure was - 0.02 (SD=2.1) for the total analytic sample. In model one testing the bivariate linear relationship between loneliness and HCC, higher loneliness via survey and EMA measures was associated with lower HCC (Survey: b= - 0.10, SE=0.03, p=.004; EMA: b= - 0.09, SE=0.03, p=.005). In model two, higher loneliness remained significantly associated with lower HCC (Survey: b= - 0.07, SE=0.03, p=.023; EMA: b= - 0.07, SE=0.03, p=.037), after controlling for the following covariates: sociodemographic factors, pubertal development and BMI, corticosteroid use, hair care practices, season of collection and assayed hair length. In model 3, youth lifetime mental health diagnosis and current psychotropic medication use were added into the regression model, and higher loneliness remained significantly associated with lower HCC (Survey: b= - 0.07, SE=0.03, p=.029; EMA: b= - 0.07, SE=0.03, p=.039). There was no effect modification by sex (Survey: b=0.04, SE=0.06, p=.552; EMA: b= - 0.01, SE=0.06, p=.843).

Conclusions: In our analysis, both survey- and EMA-reported loneliness measures were associated with lower HCC. No evidence of an interaction between sex and loneliness was observed. Future research is needed to validate these findings and investigate longitudinal relationships among adolescent loneliness, stress physiology, and downstream health sequelae.